DE505218C - Circuit for rectifying alternating currents, in which synchronously controlled mechanical contact devices or valves with rectifying effect are arranged in a Graetzsch bridge circuit - Google Patents

Description

GERMAN EMPIRE

ISSUED ON AUGUST 15, 1930

REICH PATENT OFFICE

PATENT LETTERING

M 505218 CLASS 21 d ² GROUP

C. Lorenz Akt-Ges. in Berlin-Tenipelhof *)

are arranged in Graetzscher bridge circuit

Patented in the German Empire on February 9, 1927

The subject of the present invention is a circuit arrangement for rectification of alternating currents, in which both half-waves of the current are beneficially used.

The subject matter of the invention is explained in more detail with reference to the accompanying figures, which illustrate practical exemplary embodiments. Figs. 1 and 2 relate to mechanical contact rectifiers; all other types of rectifiers can just as well be used instead. In Fig. 1, JC ₁ / C ₁ ', / C ₂ / C ₂ ', / C ₃ / C ₃ 'and / C ₄ / C / mean four resilient contact pairs, which are synchronized with the alternating frequency to be rectified , for example by a small synchronous motor driven cam disks or eccentrics and the like, or by magnets (Pendeiao rectifier) are controlled in such a way that, for example, the contact pairs K ₁ K ₁ and K ₂ / C ₂ 'open during one half period of the alternating current, the contact pairs / C ₃ K ₃ ' and K ₄ K ₄ ' are closed, while the opposite conditions occur within the other half-cycle of the alternating current. The contacts / C ₁ and / C ₃ on the one hand and the contacts Ä ""

and K ₁ on the other hand of the individual rectifier devices are connected to one another and the connection points are each led to a pole α or b on the alternating current side. In the same way, the mating contacts / C ₁ 'and / C ₄ ' or / C ₂ 'and / C ₃ ' are connected to one another and connected between points c and d of the two connecting lines of the direct current consumers, in the present example a storage battery B. As can easily be seen, the current direction through the battery B is always the same in the case of the aforementioned synchronous control of the contact devices, regardless of the polarity of the two AC terminals α and b. This circuit arrangement corresponds to the known Graetz bridge circuit.

When using the circuit arrangement described, an inconvenience has now been shown which is eliminated by the present invention. This is because if the contact pairs / C ₁ / C ₁ ', K ₂ K ₂ , / C ₈ / C ₃ ' and / C ₄ / C ₄ 'do not work completely synchronously or the rectifying effect in tubes, electrolytes and the like is not absolute , which is practically not always feasible or not with simple means, the case may arise that the power line

*) The patent seeker stated as the inventor:

Dr.-Ing. e. H. Karl Schmidt in Berlin-Lichtenrade.

be short-circuited via the mating contacts K ₁ and K _t ' or the contacts K ₂ ' and K ₃ , even if only for a short time. In order to remedy this inconvenience, according to the invention, in the parallel branches containing the valves, to which the direct current side is connected, choke coils are switched on (W ₁ , W ₂ , W ₃ and w _i according to FIG. 2). So that the unfavorable effect due to a premagnetization of the chokes by the rectified current flowing through the direct current consumer is avoided, so that the full choke effect of the coils is maintained for the above-mentioned mains short-circuit currents caused by the incorrect synchronous operation of the contacts, according to a further object of the invention the coils W ₁ , W ₂ or · ω _Ά and W _{4 are arranged} in the form of a transformer T. The chokes W ₁ and W ₂ wound in the same direction form one winding, the chokes w _s and w _{t form} the other winding of the transformer arranged above and below with opposite winding directions. The DC terminals c, d are then to be connected to the center points of the two windings.

This type of winding of the coils W ₁ , W ₂ and W ₃ , w _t in the form of a transformer is achieved that the self-induction with respect to the rectified half-waves, which are taken from the clamps c, d , is canceled because the coils : W ₁ and m _s or i S

the coils W ₂ and
W.

opposite di h

p ₂ ^ ggg

Have winding sense, while the mains short-circuit currents running through the coils W ₁ and W ₂ or W ₃ and w _i, which are wound in the same direction, have to overcome the full choke resistance and can therefore be made practically harmless by dimensioning the chokes accordingly.

The arrangement, shown in Fig. 2, is otherwise in its mode of operation with that in connection with Aibb. 1 corresponds to the device described. S ₁ and S ₂ denote two cam disks which are controlled synchronously with the alternating frequency to be rectified and which are designed so that, as illustrated in the figure, two associated contact devices are always closed alternately during a half cycle. For this purpose, the mating contacts K _1, K ₂ and K ₃ ' and K ₁ are arranged on springs which are actuated by the cam disks.

The present invention makes it possible to measure the current intensity in contact rectifiers 4 to 5 times more, without short circuits for the battery or the AC network to fear. In order to be able to use the old contacts for these high currents, a Another object of the invention several pairs of contacts connected in parallel, one can so in a simple way to form individual basic elements, which are then to be reshaped in one of the Power corresponding number can be placed on a shaft. By the way, you can in connection with the described facilities further additional devices known per se, such as choke chains, capacitors, etc. to flatten and equalize the rectified current obtained Find use.

Claims (2)

Patent claims: 1. Circuit for rectifying alternating currents, in which synchronously controlled mechanical contact devices or valves with rectifier effect in Graetzscher bridge circuit are arranged, characterized in that in each of the two branches of the bridge circuit two in the same direction - wound inductors lying in series are switched on, between which the Branch off direct current conductors and the iron core common to all coils are arranged in such a way that the currents caused by the rectified currents go Force flows counteract each other. 2. Circuit according to claim 1 with mechanical contact devices, characterized characterized in that instead of one pair of contacts there are several in parallel be used. For this purpose ι sheet of drawings Berlin, crouched in the nEicns